Symptoms and causes - Goiter - Mayo Clinic Symptoms and causes Enlarged thyroid Enlarged thyroid Widespread enlargement of your thyroid can expand the gland well beyond its normal size (outline) and may cause a noticeable bulge in your neck. Not all goiters cause signs and symptoms. When signs and symptoms do occur they may include: A visible swelling at the base of your neck that may be particularly obvious when you shave or put on makeup A tight feeling in your throat Coughing Pituitary gland and hypothalamus The pituitary gland and the hypothalamus are situated within the brain and control hormone production. Your thyroid gland produces two main hormones — thyroxine (T-4) and triiodothyronine (T-3). These hormones circulate in your bloodstream and help regulate your metabolism. They maintain the rate at which your body uses fats and carbohydrates, help control your body temperature, influence your heart rate, and help regulate the production of proteins. Your thyroid gland also produces calcitonin — a hormone that helps regulate the amount of calcium in your blood. Your pituitary gland and hypothalamus control the rate at which these hormones are produced and released.

The process begins when the hypothalamus — an area at the base of your brain that acts as a thermostat for your whole system — signals your pituitary gland to make a hormone known as thyroid-stimulating hormone (TSH). Your pituitary gland — also located at the base of your brain — releases a certain amount of TSH, depending on how much thyroxine and T-3 are in your blood. Your thyroid gland, in turn, regulates its production of hormones based on the amount of TSH it receives from the pituitary gland. Having a goiter doesn't necessarily mean that your thyroid gland isn't working normally. Even when it's enlarged, your thyroid may produce normal amounts of hormones. It might also, however, produce too much or too little thyroxine and T-3. A number of factors can cause your thyroid gland to enlarge. Among the most common are: Iodine deficiency. Iodine, which is essential for the production of thyroid hormones, is found primarily in seawater and in the soil in coastal areas.

In the developing world, people who live inland or at high elevations are often iodine deficient and can develop goiters when the thyroid enlarges in an effort to obtain more iodine. The initial iodine deficiency may be made even worse by a diet high in hormone-inhibiting foods, such as cabbage, broccoli and cauliflower. Although a lack of dietary iodine is the main cause of goiters in many parts of the world, this is not often the case in countries where iodine is routinely added to table salt and other foods. Graves' disease. A goiter can sometimes occur when your thyroid gland produces too much thyroid hormone (hyperthyroidism). In Graves' disease, antibodies produced by your immune system mistakenly attack your thyroid gland, causing it to produce excess thyroxine. This overstimulation causes the thyroid to swell. Hashimoto's disease. A goiter can also result from an underactive thyroid (hypothyroidism). Like Graves' disease, Hashimoto's disease is an autoimmune disorder. But instead of causing your thyroid to produce too much hormone, Hashimoto's damages your thyroid so that it produces too little.

Sensing a low hormone level, your pituitary gland produces more TSH to stimulate the thyroid, which then causes the gland to enlarge. Multinodular goiter. In this condition, several solid or fluid-filled lumps called nodules develop in both sides of your thyroid, resulting in overall enlargement of the gland. Solitary thyroid nodules. In this case, a single nodule develops in one part of your thyroid gland. Most nodules are noncancerous (benign) and don't lead to cancer. Thyroid cancer. Thyroid cancer is far less common than benign thyroid nodules. A biopsy of a thyroid nodule is very accurate in determining if it's cancerous. Pregnancy. A hormone produced during pregnancy, human chorionic gonadotropin (HCG), may cause your thyroid gland to enlarge slightly. Inflammation. Thyroiditis is an inflammatory condition that can cause pain and swelling in the thyroid. It may also cause an over- or underproduction of thyroxine. Risk factors Goiters can affect anyone. They may be present at birth and occur at any time throughout life. Some common risk factors for goiters include: A lack of dietary iodine.

People living in areas where iodine is in short supply and who don't have access to iodine supplements are at high risk of goiters. Being female. Because women are more prone to thyroid disorders, they're also more likely to develop goiters. Your age. Goiters are more common after age 40. Medical history. A personal or family history of autoimmune disease increases your risk. Pregnancy and menopause. For reasons that aren't entirely clear, thyroid problems are more likely to occur during pregnancy and menopause. Certain medications. Some medical treatments, including the heart drug amiodarone (Cordarone, Pacerone, others) and the psychiatric drug lithium (Lithobid, others), increase your risk. Radiation exposure. Your risk increases if you've had radiation treatments to your neck or chest area or you've been exposed to radiation in a nuclear facility, test or accident. Complications Small goiters that don't cause physical or cosmetic problems aren't a concern. But large goiters can make it hard to breathe or swallow and can cause a cough and hoarseness.

Goiters that result from other conditions, such as hypothyroidism or hyperthyroidism, can be associated with a number of symptoms, ranging from fatigue and weight gain to unintended weight loss, irritability and trouble sleeping. References Goldman L, et al., eds. Thyroid. In: Goldman-Cecil Medicine. 25th ed. Philadelphia, Pa.: Saunders Elsevier; 2016. Accessed Oct. 4, 2016. Flint PW, et al. Disorders of the thyroid gland. In: Cummings Otolaryngology: Head & Neck Surgery. 6th ed. Philadelphia, Pa.: Saunders Elsevier; 2015. Accessed Oct. 4, 2016. Medeiros-Neto G, et al. Iodine-deficiency disorders. In: Endocrinology: Adult and Pediatric. 7th ed. Philadelphia, Pa.: Saunders Elsevier; 2016. Accessed Oct. 4, 2016. Goiter. American Thyroid Association. Accessed Oct. 4, 2016. Goiter. Hormone Health Network. Accessed Oct. 4, 2016.

Iodine deficiency. American Thyroid Association. Accessed Oct. 4, 2016. Simple nontoxic goiter (euthyroid goiter). Merck Manual Professional Version. Accessed Oct. 4, 2016. Walsh JP. Managing thyroid disease in general practice. Medical Journal of Australia. 2016;205:179. Townsend CM Jr, et al. Endocrine. In: Sabiston Textbook of Surgery: The Biological Basis of Modern Surgical Practice. 19th ed. Philadelphia, Pa.: Saunders Elsevier; 2012. Accessed Oct. 6, 2016. Nippoldt TB (expert opinion). Mayo Clinic, Rochester, Minn. Oct. 26, 2016. Related Goiter: Causes, Symptoms and Treatments - Medical News Today Goiter: Causes, Symptoms and Treatments Goiter is the name given to a neck swelling produced by an abnormally enlarged thyroid gland, which has a number of causes. (The spelling used in British English is goitre.) Contents of this article: Treatments for goiter What is goiter?

Goiter is a swelling (hypertrophy) of a gland in the neck called the thyroid gland.1-3 The thyroid gland is situated in front of the windpipe and is responsible for producing and secreting hormones that regulate growth and metabolism. In rare cases, enlargement of the thyroid gland is caused by cancer , leading to a diagnosis of thyroid cancer rather than goiter.3 The degree of swelling, and the severity of symptoms produced by the goiter depend on the individual. Some cases involve a small amount of swelling, and others can involve considerable swelling that actually constricts the trachea and causes breathing problems. Most cases are categorized as 'simple' goiters that do not involve inflammation or any detriment to thyroid function, produce no symptoms, and often have no obvious cause.1-3 Fast facts on goiter Here are some key points about goiter. More detail and supporting information is in the body of this article. Goiter describes a condition where the thyroid gland, located in the neck, becomes enlarged. Iodine deficiency is the world's leading cause of goiter - but this is rare in North America. In developed countries, goiter is usually caused by an autoimmune disease.

Autoimmunity, in which the body attacks itself, causes over- or underactive thyroid, both of which lead to swelling. Goiter is usually diagnosed by physical examination, but thyroid function blood tests and scans may be used. Treatment is not necessary unless the goiter is large and causes symptoms (there are often no symptoms). Synthetic thyroid hormone is a treatment for underactive thyroid, while anti-thyroid drugs are options for an overactive gland. Surgery is rarely used as a treatment, reserved for cases that cause difficulty swallowing or breathing. What causes goiter? Iodine deficiency is the major cause of goiter worldwide, but this is rarely a cause in more economically developed countries that add iodine to salt. As iodine is inconsistently present in plant foods, vegan diets may lack sufficient iodine; this is less of a problem for vegans who live in countries such as the US that add iodine to salt).3 Rates of goiter are higher in areas where there is a deficiency of the trace mineral, which is found in seafood, plant food grown in iodine-rich soil, and cow's milk.3,4 Deficiency of iodine - found in seafood - is a major cause of goiter.

In some parts of the world, the prevalence of the condition can be as high as 80 per cent - such populations tend to be in remotely mountainous areas of southeast Asia, Latin America and central Africa, where daily intake of iodine can fall below 25 micrograms a day and children are often born with hypothyroidism .4 The thyroid gland needs iodine in order to manufacture thyroid hormones, which regulate the body's rate of metabolism.4 The main cause of goiter in developed countries is autoimmune disease.4 Women over the age of 40 are at greater risk of goiter, as are people with a family history of the condition.2 Hypothyroidism is the result of an underactive thyroid gland, and this causes goiter. Because the gland produces too little thyroid hormone, it is stimulated to produce more, leading to the swelling.3 This usually results from Hashimoto's thyroiditis/disease, a condition in which the body's immune system turns on itself and causes inflammation within the thyroid gland.2,3 Hyperthyroidism is also a cause of goiter - from an overactive thyroid gland, which produces too much thyroid hormone.

This usually happens as a result of Graves' disease , also an autoimmune disorder in which the body's immunity turns on itself and attacks the thyroid gland, causing it to swell.3 Less common causes of goiter include the following:2,3 Nodules - benign lumps, single or multiple Smoking - thiocyanate in tobacco smoke interferes with iodine absorption Hormonal changes - pregnancy, puberty and the menopause can affect thyroid function Thyroiditis - inflammation caused by infection, for example Lithium - the psychiatric drug can interfere with thyroid function Overconsumption of iodine - too much iodine can cause goiter, just as too little does Radiation therapy - particularly if to the neck. Signs and symptoms of goiter Most goiters are asymptomatic (produce no symptoms). The following are the most common symptoms that are seen with goiter:2,3 The thyroid gland. An underactive gland can cause weight gain. Throat symptoms of tightness, cough, and hoarseness Trouble swallowing ( dysphagia ) In severe cases, difficulty breathing (possibly with a high-pitch sound). Other symptoms may be present because of the underlying cause of the goiter, but they are not symptomatic of the goiter itself.

For example, if the cause is hyperthyroidism, the overactive thyroid can cause symptoms such as nervousness, palpitations, hyperactivity, increased sweating, heat hypersensitivity, fatigue , increased appetite, hair loss and weight loss.1 In cases where goiter is a result of hypothyroidism, the underactive thyroid can cause symptoms such as cold intolerance, constipation , forgetfulness, personality changes, hair loss and weight gain.1 Aside from the swelling itself, many cases of goiter present no symptoms or signs at all.2,3 Most cases are classified as simple diffuse and therefore smooth to the touch; others, classified as nodular, feel lumpy because of solid or fluid-filled lumps.3,4 Recent developments in goiter treatment Hyperthyroidism linked to heart disease risk. A study published in the Archives of Internal Medicine in April 2012 suggests that symptomless goiter is linked to higher rates of atrial fibrillation and coronary heart disease . On the next page we look at how goiter is diagnosed and the available treatments for goiter. Iodine Deficiency - American Thyroid Association Leer en Español Iodine Deficiency Iodine is an element that is needed for the production of thyroid hormone.

The body does not make iodine, so it is an essential part of your diet. Iodine is found in various foods (see Table 1 ). If you do not have enough iodine in your body, you cannot make enough thyroid hormone. Thus, iodine deficiency can lead to enlargement of the thyroid (goiter – see Goiter brochure ), hypothyroidism (see Hypothyroidism brochure ) and to mental retardation in infants and children whose mothers were iodine deficient during pregnancy. Before the 1920s, iodine deficiency was common in the Great Lakes, Appalachian, and Northwestern U.S. regions and in most of Canada. Treatment of iodine deficiency by the introduction of iodized salt has virtually eliminated the “goiter belt” in these areas. However, many other parts of the world do not have enough iodine available through their diet and iodine deficiency continues to be an important public health problem globally. Approximately 40% of the world’s population remains at risk for iodine deficiency. Iodine Deficiency FAQs WHAT ARE THE SOURCES OF IODINE? Iodine is present naturally in soil and seawater. The availability of iodine in foods differs in various regions of the world.

Individuals in the United States can maintain adequate iodine in their diet by using iodized table salt (unless they have to restrict the amount of salt in their diet), by eating foods high in iodine, particularly dairy products, seafood, meat, some breads, and eggs, and by taking a multivitamin containing iodine (see below). However, the amount of iodine in foods is not listed on food packaging in the U.S., and it can be difficult to identify sources of iodine in foods. TABLE 1. COMMON SOURCES OF DIETARY IODINE Cheese Seaweed (including kelp, dulse, nori) Shellfish WHAT ARE THE SYMPTOMS OF IODINE DEFICIENCY? All of the symptoms of iodine deficiency are related to its effect on the thyroid: GOITER – Without adequate iodine, the thyroid progressively enlarges (develops a goiter) as it tries to keep up with demand for thyroid hormone production. Worldwide, iodine deficiency is the most common cause of thyroid enlargement and goiter (see Goiter brochure ). Within a goiter, nodules can develop.

Patients with a large goiter may experience symptoms of choking, especially when lying down, and difficulty swallowing and breathing. HYPOTHYROIDISM – As the body’s iodine levels fall, hypothyroidism may develop, since iodine is essential for making thyroid hormone. While this is uncommon in the United States, iodine deficiency is the most common cause of hypothyroidism worldwide (see Hypothyroidism brochure). PREGNANCY-RELATED PROBLEMS – Iodine deficiency is especially important in women who are pregnant or nursing their infants. Severe iodine deficiency in the mother has been associated with miscarriages, stillbirth, preterm delivery, and congenital abnormalities in their babies. Children of mothers with severe iodine deficiency during pregnancy can have mental retardation and problems with growth, hearing, and speech. In the most severe form, an underactive thyroid can result in cretinism (a syndrome characterized by permanent brain damage, mental retardation, deaf mutism, spasticity, and short stature), though this is not seen in the United States. Congenital hypothyroidism due to iodine deficiency is the most common preventable cause of mental retardation in the world.

Even mild iodine deficiency during pregnancy, which may be present in some women in the United States, may be associated with low intelligence in children. WHAT ARE THE CAUSES OF IODINE DEFICIENCY? Since the body does not make iodine, it relies on the diet to have enough iodine. The availability of iodine in foods differs in various regions of the world. Individuals in the U.S. can maintain adequate iodine in their diet by using iodized table salt (unless they have to restrict the amount of salt in their diet), by eating foods high in iodine, particularly dairy products, seafood, meat, some breads, and eggs, and by taking a multivitamin containing iodine. However, the amount of iodine in foods is not listed on food packaging in the U.S., and it can be difficult to identify sources of iodine in foods. See the Iodine Deficiency Brochure for a list of food items rich in iodine. HOW DO YOU DIAGNOSE IODINE DEFICIENCY? Iodine deficiency is diagnosed across populations and not specifically in individuals.

Since iodine is released from the body through the urine, the best way to determine iodine deficiency across a large population is to measure the amounts of iodine in urine samples. Iodine deficiency is defined as a median urinary iodine concentration less than 50 μg/L in a population ( see Table 2 ). In the United States, iodine status has remained generally adequate in the last 2 decades although studies have shown that urinary iodine levels dropped by about half between the early 1970s and the early 1990s. However, iodine deficiency is a major issue in other parts of the world, including parts of Europe, Africa and Asia. TABLE 2. MEDIAN POPULATION URINARY IODINE VALUES AND IODINE NUTRITION MEDIAN URINARY IODINE CONCENTRATION (μg/L) CORRESPONDING IODINE INTAKE (μg/day) HOW IS IODINE DEFICIENCY TREATED? There are no tests to confirm if you have enough iodine in your body. When iodine deficiency is seen in an entire population, it is best managed by ensuring that common foods that people eat contain sufficient levels of iodine.

Since even mild deficiency during pregnancy can have effects on delivery and the developing baby, all pregnant and breastfeeding women should take a multivitamin containing at least 150 μg iodine per day. HOW IS IODINE DEFICIENCY PREVENTED? As with many diseases, it is better to prevent the problem rather than have to treat it. Over the last 80 years, world-wide efforts have been made to eliminate iodine deficiency. Indeed, elimination of iodine deficiency has been a major goal of the World Health Organization. Iodized salt has been the mainstay of treatment for iodine deficiency worldwide, including in the United States. Injections of iodized oil are occasionally used in regions of the world where widespread iodized salt use is not possible. Iodination of water supplies also has been effective in some places. UNITED STATES RECOMMENDATIONS – The Institute of Medicine has set the Recommended Dietary Allowance (RDA) for iodine in adult men and women at 150 μg per day. Individuals who add tablet salt to their food regularly should use iodized salt. One teaspoon of iodized salt contains approximately 400 μg iodine.

Most iodine-containing multivitamins have at least 150 μg iodine, but only about half of the types of multivitamins in the U.S. contain iodine. The RDA is 220 μg iodine per day for pregnant women and 290 μg iodine per day for breastfeeding women. Because the effects of iodine deficiency are most severe in pregnant women and their babies, the American Thyroid Association has recommended that all pregnant and breastfeeding women in the U.S. and Canada take a prenatal multivitamin containing 150 μg iodine per day. ARE THERE PROBLEMS WITH TAKING TOO MUCH IODINE? Taking too much iodine can also cause problems. This is especially true in individuals that already have thyroid problems, such as nodules, hyperthyroidism and autoimmune thyroid disease. Administration of large amounts of iodine through medications (ie Amiodarone), radiology procedures (iodinated intravenous dye) and dietary excess (Dulse, kelp) can cause or worsen hyperthyroidism and hypothyroidism.

In addition, individuals who move from an iodine-deficient region (for example, parts of Europe) to a region with adequate iodine intake (for example, the United States) may also develop thyroid problems since their thyroids have become very good at taking up and using small amounts of iodine. In particular, these patients may develop iodine-induced hyperthyroidism (see Hyperthyroidism brochure ). Causes of goitre - Health Exchange Causes of goitre Symptoms of goitre Causes of goitre There are several causes of goitre, which is a swollen thyroid gland. Sometimes no definite cause can be found. Iodine deficiency Iodine deficiency used to be the major cause of goitres, but it is now rare in England due to changes in our diet. It remains a significant problem in parts of the developing world. Iodine is a trace element found in seawater and soil. It enters the food chain through plants that grow in iodine-rich soil, or through fish or plants from the sea.

Iodine is found in: seafood, such as fish, shellfish or seaweed plant foods, such as cereals or grains cow’s milk The thyroid gland (a gland in the neck that produces hormones) needs iodine to help manufacture thyroid hormones (chemicals released into the bloodstream that control the body’s growth and metabolism). If your body does not receive enough iodine, your thyroid gland becomes underactive, and will expand in order to produce more thyroid hormones. In the UK, iodine deficiency used to be a common problem until the early 1900s, when salt manufactures started to add small amounts of iodine to salt, which reduced the number of cases. However, in recent years, the number of people experiencing iodine deficiency in the UK has started to rise. This could be due to an increased number of people preferring a low-salt, non-dairy diet. Iodine deficiency can be a problem for people following a strict vegan diet. Overactive thyroid gland A goitre can develop if the thyroid gland becomes overactive (hyperthyroidism), leading to too many thyroid hormones being produced. Increased hormone production over-stimulates the thyroid gland and causes it to swell.

The leading cause of hyperthyroidism is a condition called Graves’ disease. Graves’ disease causes your immune system (the body’s natural defence system) to send antibodies (proteins that fight infections) to your thyroid gland. The antibodies stimulate the thyroid gland, causing an increased amount of thyroid hormones to be released. See hyperthyroidism for more information about this condition. Underactive thyroid gland A goitre can also develop if the thyroid gland becomes underactive (hypothyroidism). If the thyroid gland does not produce enough thyroid hormones, the body will stimulate it to produce more. This can cause the thyroid gland to swell. As well as iodine deficiency, one of the leading causes of hypothyroidism is a condition called Hashimoto’s thyroiditis , sometimes known as Hashimoto’s disease. As with Graves’ disease, Hashimoto’s thyroiditis is an autoimmune disease. Rather than over-stimulating the gland, Hashimoto’s thyroiditis interferes with the gland’s ability to produce hormones. In order to compensate for this, the body causes the gland to swell, resulting in a goitre. Read more about Hashimoto’s thyroiditis . Smoking There may also be a link between smoking and an increased risk of developing a goitre.

This may be because tobacco smoke contains a chemical called thiocyanate, which can interfere with the body’s ability to make use of iodine. Smokers who have a low-iodine diet are particularly at risk. See quitting smoking for help to stop smoking. Other causes A number of other causes have been linked to goitres. These are outlined below. Pregnancy and puberty The changes in hormone levels that occur during pregnancy and puberty (when a child gradually progresses to a sexually developed adult) can affect the thyroid gland. Lithium Lithium is a medicine often used to treat a number of mental health conditions, such as depression and bipolar disorder (a condition that affects your moods, which can swing from one extreme to another). Lithium can interfere with how your thyroid gland functions. Infection A number of bacteria, parasites and fungi that cause infections are also known to cause goitres. Excessive iodine An excessive amount of iodine can build up in the body as a result of eating too much iodine-rich food. For example seaweed, particularly kelp (a type of brown seaweed that contains many different minerals), is a rich source of iodine. An excess amount of iodine can affect the thyroid gland.

Exposure to radiation Exposure to radiation (energy waves that travel through the air) can sometimes cause goitres. Radiation is used to treat some health conditions ( radiotherapy ), such as cancer. Receiving radiotherapy to the neck can sometimes cause goitres. Non-cancerous growths Goiter - simple: MedlinePlus Medical Encyclopedia Cigarette smoking Certain foods (soy, peanuts, vegetables in the broccoli and cabbage family) Toxic nodular goiter, an enlarged thyroid gland that has a small, rounded growth or many growths called nodules, which produce too much thyroid hormone Simple goiters are more common in: People over age 40 People with a family history of goiter Women Symptoms The main symptom is an enlarged thyroid gland. The size may range from a single small nodule to a large mass at the front of the neck. Some people with a simple goiter may have symptoms of an underactive thyroid gland. In rare cases, an enlarged thyroid can put pressure on the windpipe (trachea) and food tube (esophagus).

This can lead to: Breathing difficulties (with very large goiters), especially when lying flat on the back Cough Swallowing difficulties, especially with solid food Pain in the area of the thyroid Exams and Tests The health care provider will do a physical exam. This involves feeling your neck as you swallow. Swelling in the area of the thyroid may be felt. If you have a very large goiter, you may have pressure on your neck veins. As a result, when the provider asks you to raise your arms above your head, you may feel dizzy. Blood tests may be ordered to measure thyroid function: If nodules are found on an ultrasound, a biopsy may be needed to check for thyroid cancer. Treatment A goiter only needs to be treated if it is causing symptoms.

Treatments for an enlarged thyroid include: Thyroid hormone replacement pills if the goiter is due to an underactive thyroid Small doses of Lugol's iodine or potassium iodine solution if the goiter is due to a lack of iodine Radioactive iodine to shrink the gland, especially if the thyroid is producing too much thyroid hormone Surgery ( thyroidectomy ) to remove all or part of the gland Outlook (Prognosis) A simple goiter may disappear on its own, or may become larger. Over time, the thyroid gland may stop making enough thyroid hormone. This condition is called hypothyroidism . In some cases, a goiter becomes toxic and produces thyroid hormone on its own. This can cause high levels of thyroid hormone, a condition called hyperthyroidism . When to Contact a Medical Professional Call your provider if you experience any swelling in the front of your neck or any other symptoms of goiter. Prevention Using iodized table salt prevents most simple goiters. Alternative Names Simple goiter; Endemic goiter; Colloidal goiter; Nontoxic goiter Images Thyroid gland References Hegedüs L, Paschke R, Krohn K, Bonnema SJ. Multinodular goiter.

In: Jameson JL, De Groot LJ, de Kretser DM, et al, eds. Endocrinology: Adult and Pediatric. 7th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 90. Kim M, Ladenson PW. Thyroid. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 226. Read More You & Your Hormones | Endocrine conditions | Goitre You & Your Hormones Email article to a friend | Last updated: January 08, 2015 Goitre is a general term for an enlarged thyroid gland. Depending on the type of swelling, location, how it affects gland function and how long it has been present, goitre has various effects and is treated in a variety of different ways. Swollen neck of a patient with goitre. Alternative names for goitre Goiter; thyroid cyst; colloid goitre; colloid goiter; Plummer disease; Plummer’s disease; follicular adenoma . What is goitre? The thyroid gland is a butterfly-shaped gland found in the neck.

A normal thyroid is usually not felt if finger pressure is applied to the neck. Any increase in size of the thyroid gland is called goitre. Goitre can be due to enlargement of the whole thyroid gland, known as ‘smooth goitre’, or part of the gland, called a ‘nodular’ or ‘cystic’ goitre. Many people with goitre have normal thyroid hormone levels but some can have an underactive ( hypothyroidism ) or an overactive thyroid ( hyperthyroidism ). What causes goitre? There are a number of different causes for goitre including: Iodine deficiency - Iodine is an essential trace element which helps the thyroid gland function properly and make thyroid hormones. There are two main hormones called thyroxine and triiodothyronine . Approximately 2.2 billion people worldwide have this type of deficiency and roughly 29% of the world's population live in an iodine deficient area. In the UK, our diet is supplemented with iodine and most areas have enough iodine. Goitres may be due to one of the following: Thyroiditis - This means inflammation of the thyroid gland. A number of causes can lead to swelling of the thyroid.

The most common cause worldwide is Hashimoto's thyroiditis which is due to the body reacting against itself and forming antibodies (known as the autoimmune process), which attack the thyroid gland. Thyroiditis can also occur for other reasons eg, due to a viral infection. Graves' disease – This is an autoimmune disease where the body produces antibodies causing the thyroid to be overactive. Benign growths - These can take a number of different forms but follicular adenomas are most common. There may be more than one growth and they can be fluid or blood-filled, but they are usually single cyst-type or solid growths. Goitrogens - These are external factors that may cause the formation of goitre. They include drugs (eg, lithium, which is used in the treatment of mental health problems) and certain foods such as vegetables from the cabbage family, cassava or kelp, although only excessively high consumption of these could lead to goitre formation. Additionally, a lack of micronutrients such as iron, selenium, and vitamin A could also cause goitre formation. Physiological causes – These include increased demands for hormone production during pregnancy and puberty. Inherited causes – There are a number of genetic conditions that can increase the possibility of goitre formation.

Toxic nodular goitre (Plummer’s disease) – This is where a nodule is associated with overactivity of the thyroid gland. What are the signs and symptoms of goitre? It is common to have small nodules within the thyroid gland, which cannot be felt by finger pressure, but these may be picked up by chance when scans or examinations are conducted for other reasons. In these cases, there have usually been no symptoms to indicate the presence of goitre. Larger goitres simply present as a lump in the neck. How common is goitre? Worldwide, goitre is estimated by the World Health Organization to affect around 12% of people, although the rate of goitre in Europe as a whole is slightly lower. Goitre affecting a particular area (endemic) occurs in areas where there is iodine deficiency and is defined when more than one in ten people have goitre. Is goitre inherited? Some forms of goitre can be inherited. There is some evidence that the presence of goitre in one family member increases the chances of other family members having goitre. How is goitre diagnosed? Goitre is diagnosed when the thyroid gland is enlarged enough to be felt by external touch or is clearly visible without a scan.

Usually a GP will undertake thyroid function tests to measure the levels of thyroid related hormones and thyroid antibodies in the bloodstream. They may also arrange an ultrasound scan or make a referral to an endocrinologist for outpatient assessment. Where more complex tests are required, they may include: ‘ Fine needle aspiration ’ of the thyroid gland. A needle is carefully guided to remove a small amount of thyroid tissue which is studied under a microscope to determine the cell type(s) that are present. This procedure may need to be repeated more than once to get an adequate result. A thyroid 'uptake' scan, which is conducted by a radiologist. This will pick up differences in the absorption of special chemicals such as radioiodine as well as the activity of different areas of the thyroid. How is goitre treated? Treatment depends on the underlying cause of the goitre. ‘Simple’ goitre, where there is no thyroid hormone imbalance and no problems arising from the size of the thyroid, can usually just be regularly monitored and is unlikely to cause problems. Where treatment is requested for cosmetic reasons, surgery (a thyroidectomy) is occasionally suggested, although totoal removal of the thyroid gland will result in the patient requiring lifelong thyroxine replacement.

Treatment of overactive and underactive thyroid is explained in articles on hyperthyroidism and hypothyroidism respectively. Are there any side-effects to the treatment? The majority of patients respond well to treatment and do not experience any side-effects. A fine needle aspiration is usually conducted without any problems and only causes minor discomfort to the patient. Surgery carries the normal risks of any operation (the risks from anaesthetic , post-operative infection, haemorrhage, bleeding and scar formation), and may lead to an underactive thyroid. It can rarely cause specific complications with damage to the recurrent laryngeal nerve (controlling the voice box) resulting in a hoarse voice, or damage to the glands around the thyroid ( parathyroid glands ) which control calcium. This may result in a low calcium level ( hypocalcaemia ) in the blood requiring medication. What are the longer-term implications of goitre? Occasionally, a large goitre will press on nearby structures, for instance making it difficult to swallow. If that happens, it may be appropriate to consider surgery. Usually there are no long-term implications of goitre, and the safest thing is to avoid unnecessary surgery once medical assessment has been made.

Iodine Deficiency: Background, Pathophysiology, Epidemiology Iodine Deficiency Author: Stephanie L Lee, MD, PhD; Chief Editor: George T Griffing, MD more... Share Overview Background Severe iodine deficiency results in impaired thyroid hormone synthesis and/or thyroid enlargement (goiter). Population effects of severe iodine deficiency, termed iodine deficiency disorders (IDDs), include endemic goiter, hypothyroidism, cretinism, decreased fertility rate, increased infant mortality, and mental retardation. (See Pathophysiology and Presentation.) [ 1 ] Iodine is a chemical element. It is found in trace amounts in the human body, in which its only known function is in the synthesis of thyroid hormones. Iodine is obtained primarily through the diet but is also a component of some medications, such as radiology contrast agents, iodophor cleansers, and amiodarone. (See Etiology.) Worldwide, the soil in large geographic areas is deficient in iodine. Twenty-nine percent of the world’s population, living in approximately 130 countries, is estimated to live in areas of deficiency (see the Table).

[ 2 ] This occurs primarily in mountainous regions such as the Himalayas, the European Alps, and the Andes, where iodine has been washed away by glaciation and flooding. Iodine deficiency also occurs in lowland regions far from the oceans, such as central Africa and Eastern Europe. Persons who consume only locally produced foods in these areas are at risk for IDD. See the distribution of iodine deficiency in the image below. (See Epidemiology.) Distribution of iodine deficiency in developing countries. + + Adapted from the World Health Organization (WHO)/United Nations Children's Fund (UNICEF)/International Council for Control of Iodine Deficiency Disorders (ICCIDD). Normal dietary iodine intake is 100-150 mcg/day.

The US Institute of Medicine’s (IOM’s) recommended dietary allowance (RDA) of iodine is as follows: Adults and adolescents - 150 mcg/day Pregnant women - 220 mcg/day Children aged 1-11 years - 90-120 mcg/day Infants - Adequate intake is 110-130 mcg/day WHO’s recommendations are similar, although the organization recommends 200 mcg/day for pregnant or lactating women and 50-90 mcg/day for infants younger than 1 year. [ 3 ] Sources of dietary iodine In areas where iodine is not added to the water supply or food products meant for humans or domesticated animals, the primary sources of dietary iodine are saltwater fish, seaweed, and trace amounts in grains. The upper limit of safe daily iodine intake is 1100 mcg/day for adults; it is lower for children. [ 4 , 5 , 6 , 7 ] In the United States, iodine has been voluntarily supplemented in table salt (70 mcg/g).

Salt was selected as the medium for iodine supplementation because intake is uniform across all socioeconomic strata and across seasons of the year, supplementation is achieved using simple technology, and the program is inexpensive. The estimated annual cost of iodine supplementation of salt in the United States is $0.04 per person. (See Treatment and Medication.) Other major sources of dietary iodine in the United States are egg yolks, milk, and milk products because of iodine supplementation in chicken feed, the treatment of milk cows and cattle with supplemental dietary iodine to prevent hoof rot and increase fertility, and the use of iodophor cleaners by the dairy industry. [ 8 ] Changes in US iodine intake In the early 1900s, the Great Lakes, Appalachian, and northwestern regions of the United States were endemic regions for IDD, but since the iodization of salt and other foods in the 1920s, dietary iodine levels generally have been adequate. However, sustaining these iodization programs has become a concern.

Data collected in the United States by National Health and Nutrition Examination Survey I (NHANES I) for the years 1971-1974 showed that the median urinary iodine level was 320 mcg/L, reflecting adequate dietary iodine intake. [ 9 ] However, by the time of NHANES III (1988-1994), the median urinary iodine value had fallen to 145 mcg/L. The reduction in US dietary iodine intake since the 1970s has likely been the result of the removal of iodate conditioners in store-bought breads, widely publicized recommendations for reduced salt and egg intake for blood pressure and cholesterol control, the increasing use of noniodized salt in manufactured or premade convenience foods, decreased iodine supplementation of cattle feed, poor education about the medical necessity of using iodized salt, and reduction in the number of meals made at home.

[ 9 , 10 , 11 ] The NHANES surveys of 2001-2002, 2005-2006, and 2007-2008 showed that US dietary iodine intake has stabilized. [ 10 , 11 ] Although the most recent NHANES survey reveals adequate iodine intake in the general US population, certain groups have an insufficient intake of iodine, such as pregnant women, who were found to have a median urinary iodine concentration of 125 mcg/L). [ 12 ] Population-based assessment and treatment In population-based assessments, iodine sufficiency can be determined based on the results of a spot urine test for iodine and creatinine. [ 10 ] Supplementation can be achieved by using iodized salt in cooking or a once-daily multiple vitamin containing sodium iodide. (See Workup, Treatment, and Medication.) [ 4 , 13 ] Pediatric considerations Iodine stores within the thyroid increase with age in pediatric patients. Therefore, infants and young children tend to have higher131 I uptake than do adults.

Additionally, newborns and young infants are much more severely affected by iodine deficiency than are adults and are more likely to become overtly hypothyroid. (See Presentation.) Prenatal considerations Women with severe iodine deficiency are more likely to experience infertility, and pregnancy in this group is more likely to result in miscarriage or congenital anomalies. Thyroid hormones are essential for fetal brain growth and development, and severe maternal iodine deficiency may lead to mental and growth retardation or cretinism in offspring, and even mild maternal iodine deficiency has been associated with lower IQ in children. [ 14 ] Even in areas of borderline iodine intake, as many as 10% of women may develop goiter during pregnancy. (See Presentation.) Patient education The public must understand the importance of using iodized salt, especially in the United States, where iodization of salt is not mandated by law. Several areas of the world, including the United States, Australia, and the Netherlands, where iodine deficiency was eradicated by voluntary methods, have later shown a significant decrease in iodine intake. For patient education information, see the Thyroid and Metabolism Center and the Pregnancy Center , as well as Thyroid Problems and Miscarriage .

Next: Pathophysiology Dietary iodine is taken up readily through the gut in the form of iodide. From the circulation, it is concentrated in the thyroid gland by means of an energy-dependent sodium-iodate symporter. In the follicle cells of the thyroid gland, 4 atoms of iodine are incorporated into each molecule of thyroxine (T4) and 3 atoms into each molecule of triiodothyronine (T3). These hormones are essential for neuronal development, sexual development, and growth and for regulating the metabolic rate, body heat, and energy. When dietary iodine intake is inadequate for thyroid hormone synthesis, the serum T4 level initially falls and a number of processes ensue to restore adequate thyroid hormone production. The pituitary gland senses low levels of circulating T4 and releases more thyroid-stimulating hormone (TSH). TSH stimulates the growth and metabolic activity of thyroid follicular cells. TSH stimulates each cell to increase iodine uptake and thyroid hormone synthesis and secretion. Increased TSH levels and reduction of iodine stores within the thyroid result in increased T3 production relative to T4 production.

T3 is 20-100 times more biologically active than T4 and requires fewer atoms of iodine for biosynthesis. The increased production T 3 results in the maintenance of normal levels of thyroid hormone bioactivity despite the reduction in T 4 because of iodine deficiency. These processes tend to conserve iodine stores and help maintain normal thyroid function. In addition, thyroid hormones are deiodinated in the liver, and the iodine is released back into the circulation for reuptake and reuse by the thyroid gland. Even under these circumstances, iodine is passively lost in the urine, with additional small (10%) losses from biliary secretion into the gut. Goiter development and hyperthyroidism Enlargement of the thyroid gland begins as an adaptive process to low iodine intake. Iodine deficiency is the most common cause of goiter in the world. The goiter initially is diffuse, but it eventually becomes nodular. Some nodules may become autonomous and secrete thyroid hormone regardless of the TSH level. These autonomous nodules have been demonstrated to frequently contain TSH-activating mutations. Initially, thyroid hormone output by the normal thyroid surrounding the autonomous nodules is reduced to maintain euthyroidism.

Autonomous nodules may cause hyperthyroidism . High levels of iodine, such as those found in radiographic contrast dyes or amiodarone, may cause hyperthyroidism in the setting of nodular goiter with “hot” or autonomous nodules or hypothyroidism in the setting of autoimmune thyroid disease. If the total output of thyroid hormone by the autonomous nodules exceeds that of the normal thyroid gland, the patient becomes biochemically hyperthyroid. This condition is known as a toxic multinodular goiter. Hypothyroidism When iodine deficiency is more severe, thyroid hormone production falls and the patient may experience a hypothyroid condition. In such cases, adults have the usual signs and symptoms of hypothyroidism. However, congenital hypothyroidism (also known as cretinism) in fetuses and young children prevents central nervous system development and maturation, resulting in permanent mental retardation, neurologic defects, and growth abnormalities.

[ 4 , 15 ] Previous Epidemiology Occurrence in the United States Early in the 20th century, the Great Lakes, Appalachian, and northwestern regions of the United States were endemic for iodine deficiency disorders, but since the iodization of salt and other foods in the 1920s, dietary iodine levels generally have been adequate. National survey data suggest that average US dietary iodine intake fell dramatically from 1971-1990 and then stabilized. Urinary iodine values of less than 50 mcg/L, moderate iodine deficiency, are found in 11.1% of the total population, 7.3% of pregnant women, and 16.8% of reproductive-aged women. [ 9 , 10 ] International occurrence Internationally, 2.2 billion people worldwide are at risk for IDD. Of these persons, 30-70% have goiter and 1-10% have cretinism.

The clinical disorders of iodine deficiency tend to be more profound in geographic areas associated with coexisting selenium and vitamin A deficiencies and in regions where goitrogens, such as cassava or millet, are major staples of the diet. Race-, sex-, and age-related demographics No race predilection exists for IDD; prevalence is affected only by geographic area and diet. After age 10 years, the prevalence of goiter is higher in girls than in boys in areas of iodine deficiency. No sex-based difference is observed in the incidence of cretinism. Patients of any age can be affected by iodine deficiency. The most devastating complications of iodine deficiency disorder occur when iodine is deficient during fetal and neonatal growth. Previous Next: Prognosis The supplementation of iodine does not reverse cretinism or reduce the size of large nodular goiters. Small, diffuse goiters of short duration that occur in infants or during pregnancy appear to be managed effectively with iodine supplementation. Iodine deficiency can recur if iodine supplementation programs lapse. [ 16 ] Recurrence of goiter and new cases of cretinism have been noted in some nations where this has occurred.

These changes are manifested prominently in school-aged children, who are particularly sensitive to variations in iodine intake. Thyroid volume, prevalence of goiter, and urinary iodine levels may return to pre-iodine supplementation levels 1-2 years following the discontinuation of iodine supplementation. Morbidity Mild to moderate IDD can cause thyroid function abnormalities and endemic goiter. In areas with severe endemic IDD, rates of miscarriage and infant mortality are increased. Cretinism is rare, but populations in which severe iodine deficiency is prevalent are at risk for reduced intelligence and mental retardation. In fact, iodine deficiency is the leading cause of preventable mental retardation worldwide. Whether iodine deficiency causes an increased risk for thyroid cancer is unclear, but a higher proportion of more aggressive thyroid cancers (ie, follicular thyroid carcinoma) and an increased thyroid cancer mortality rate are found in areas where iodine deficiency is endemic.

Previous Contributor Information and Disclosures Author Stephanie L Lee, MD, PhD Associate Professor, Department of Medicine, Boston University School of Medicine; Director of Thyroid Health Center, Section of Endocrinology, Diabetes and Nutrition, Boston Medical Center; Fellow, Association of Clinical Endocrinology Stephanie L Lee, MD, PhD is a member of the following medical societies: American College of Endocrinology , American Thyroid Association , Endocrine Society Disclosure: Nothing to disclose. Coauthor(s) Sonia Ananthakrishnan, MD Assistant Professor of Medicine, Section of Endocrinology, Diabetes and Nutrition, Boston Medical Center, Boston University School of Medicine Disclosure: Nothing to disclose. Elizabeth N Pearce, MD, MSc Associate Professor of Medicine, Boston Medical Center, Boston University School of Medicine Elizabeth N Pearce, MD, MSc is a member of the following medical societies: American Association of Clinical Endocrinologists , American Thyroid Association , Endocrine Society , Massachusetts Medical Society Disclosure: Serve(d) as a director, officer, partner, employee, advisor, consultant or trustee for: consulted for Scientific Consulting Company GmbH; advisory board for Endocrine Advisor Website; Member of the Management Council of the Iodine Global Network.

Chief Editor George T Griffing, MD Professor Emeritus of Medicine, St Louis University School of Medicine Disclosure: Nothing to disclose. Acknowledgements Arthur B Chausmer, MD, PhD, FACP, FACE, FACN, CNS Professor of Medicine (Endocrinology, Adj), Johns Hopkins School of Medicine; Affiliate Research Professor, Bioinformatics and Computational Biology Program, School of Computational Sciences, George Mason University; Principal, C/A Informatics, LLC Arthur B Chausmer, MD, PhD, FACP, FACE, FACN, CNS is a member of the following medical societies: American Association of Clinical Endocrinologists , American College of Endocrinology , American College of Nutrition , American College of Physicians , American College of Physicians-American Society of Internal Medicine , American Medical Informatics Association , American Society for Bone and Mineral Research , Endocrine Society , and International Society for Clinical Densitometry Disclosure: Nothing to disclose. Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference Disclosure: Medscape Salary Employment Iodine Deficiency - Symptoms, Causes, Treatments Iodine Deficiency Treatments What is iodine deficiency?

Iodine is an element your thyroid needs to make thyroid hormones. If your diet is deficient in iodine, your thyroid gland will enlarge as it tries to increase the production of thyroid hormones. The enlarged thyroid can cause a mass in the neck known as a goiter. As thyroid levels fall, hypothyroidism develops. Hypothyroidism slows your metabolism, causing such symptoms as fatigue, weight gain, weakness, increased cold sensitivity, constipation, dry skin, and depressed mood. Your hair and nails may be thin and brittle and, if you are female, your menstrual cycle may become abnormal. Left untreated, your skin may swell and thicken, your eyes may seem to protrude, mental function may decline, and you may ultimately lapse into a coma. Looking for a Doctor? Search Now Find a Nutritionist Near You Iodine is also critical for development. Babies born of mothers who have an iodine deficiency may have problems, such as mental retardation, deaf-mutism, gait abnormalities, and growth abnormalities. Infants and children who do not get enough iodine may also have cognitive difficulties, but those may be reversible.

The 10 Best Sources of Protein Iodine deficiency is rare in the United States, partly because table salt is often iodized. Dairy products, eggs, seafood, seaweed, some meats, and some breads are also dietary sources of iodine. The best method of treating iodine deficiency is avoiding it in the first place. If it develops, however, it can be treated with iodine supplementation and dietary modifications. Severe complications of iodine deficiency are rare in the United States. If you notice an enlarging mass in your neck or develop symptoms suggestive of hypothyroidism, seek prompt medical care. Severe depression, difficulty breathing, chest pain or pressure, change in mental status, and change in level of consciousness are complications of hypothyroidism that, rarely, may develop as a result of long-standing iodine deficiency. If these symptoms develop, seek immediate medical care (call 911). Severe iodine deficiency also increases the risk of miscarriage and stillbirth; seek immediate medical care for any bleeding during pregnancy or concerns about fetal well-being.

Question: A deficiency of which element causes goitre?
Answer: Iodine